A rapid and inexpensive 96-well DNA-extraction method from blood using silicon dioxide powder (Glassmilk).

We present a rapid high-throughput DNA extraction method for use with EDTA-anticoagulated blood using silicon dioxide (SiO₂) powder in a guanidine-HCl solution, hereinafter referred to as "Glassmilk." The method utilizes a 96-well deep-well plate, enabling DNA extraction from 96 samples in under 3 h. The method integrates cell lysis, washing, elution, and DNA storage within the same well, eliminating the need for DNA transfer. The Glassmilk extraction method is cost-effective and fast, and it avoids expensive or toxic reagents by using only basic lab equipment. The method yielded approximately 40 μg of high-quality DNA from 200 μl of blood. The DNA yield of the Glassmilk method was about 50% higher, and the purity of the DNA was comparable to those obtained using two commercial column-based extraction kits that were used for comparison. The cost per sample was around $1, with the most expensive item being the filter pipette tips, which account for about $0.80 per sample. As we show, the extracted DNA is suitable for downstream applications such as polymerase chain reaction (PCR), PCR-restriction fragment length polymorphism analysis, and qPCR. The method can be adapted for various sample types, including biopsies, fecal samples, cultured cells, and bacteria (see "subprotocols" section), and can also be applied in individual Eppendorf tubes. Our protocol may be useful for basic molecular research in laboratories having limited funds.